Refrigerating apparatus and method



Jan. 10, 1933.

J. 5. BELT 1,893,483

REFRIGERATING APPARATUS AND METHOD Filed Jan. 5, 1951 i I N VEN TOR.

A TTORNEY.

Patented Jan. 10, 1933 UNITED STATES Lamas PATENT OFFICE Applicationfiled January 5, 1931.

This invention relates to a refrigerating apparatus and method, whereinsoli carbon dioxide, a very intense refrigerant, 1s employed.

The present invention contemplates a refrigerating apparatus and methodin which the solid carbon dioxide and the material or articles to berefrigerated are separated by a heat insulation which is slightly butnot highly pervious to the gas resulting from sublimation of the solidcarbon dioxide, and wherein the thickness of such insulation isadjustably varied to regulate the degree of refrigeration impartedto thematerial or articles to be refrigerated. By varying the thickness of theheat insulation between the solid carbon dioxide and the material orarticles to be refrigerated, the speed of sublimation of thesolid carbondioxide is controlled go because the thickness of the heat insulationwill govern the speed with which said walls absorb heat from thematerial or articles to be refrigerated, and because the thickness ofsuch insulation will govern the speed with which the gas evolved fromthe frozen carbon dioxide will pass therefrom through the heatinsulation to the material or articles to be refrigerated. In apractical embodiment of the invention, the insulation may divide arefrigerator into an upper chamber for reception of the solid carbondioxide and a lower chamber for reception of the material or articles tobe refrigerated, said lower chamber having a bottom gas outlet 85 withwhich is associated means to adjustably regulate. the escape of gas.Because of the greater weight of the gas as compared to the weight ofair within the refrigerator, it is apparent that when the sublimation ofthe solid carbon dioxide takes place at atmospheric pressure in therefrigerator, the gas will pass downwardly to and through the heatinsulation into the lower chamber containing the material or articles tobe refrig- 4 erated, the gas exhausting from the latter chamber throughits bottom outlet. The low temperature imparted to the lower chambercontaining the material or articles to be refrigerated is to a greatextent caused by the chilling of the heat insulation between the SerialNo. 506,806.

chambers and consequent absorption of heat from the material or articlesby the insulation. To this is added the refrigerating effect of the gasdirectly upon the materials or articles as it slowly seeps through theheat insulation.

The aboveand other features of my invention will be readily understoodfrom the following description when considered in connection with theaccompanying drawing, in which:

Figure 1 is a front elevational view, partly broken away, of an uprightrefrigerator of the domestic type embodying the present invention.

Figure 2 is a vertical section taken substantially upon line 2-2 ofFigure 1; and

Figure 3 is an enlarged fragmentarybottom plan view illustrating thedamper for regulating the escape of gas from the bottom of the chamberfor the material or articles to be refrigerated.

Referring more in detail to the drawing, a refrigerator of the uprighttype is conventi-onally shown, the same comprising a con- 75 tainer orbox-like structure 5 whose walls are of any suitable heatinsulatingconstruction. The interior of the refrigerator is divided intonon-communicating upper and lower compartments by means of heatinsulation of adjustable thickness, the upper compartment v6 beingadapted to receive the solid carbon dioxide, and the lower compartment 7being adapted to receive the material or articles to be refrigerated. Asuitable 85 fora-ruinous support 8 is provided in the up er chamber 6 onwhich the block of solid car on dioxide D may be placed, therefrigerator having a top openin closed by a suit able rubstantiallyair-tig t cover 9 and through which the solid carbon dioxide may beplaced into the chamber 6 upon the support 8. The lower chamber 7 mayhave suitable article or food-supporting racks l0 and a frontsubstantially air-tight door 11.

As shown, the heat insulation which divides the interior of therefrigerator intothe upper and lower compartments 6 and 7 is preferablyin the nature of a plurality of horizontal removable partitions 12selectively slidably insertible or removable through the front wall ofthe refrigerator, said partitions bein made of cork board or othersuitable insu ating material which is slightly but not hi hly perviousto the gas evolved from the so id carbon dioxide as it sublimatesdirectly to a gas. Obviously, by varying the number of division platesor partitions 12 in use, the effective thickness of the heat insulationinterposed between the two chambers 6 and 7 may be varied withinreasonable limits so as to control the approximate temperature whichwill maintain within the lower com gartment 7, and to consequentlcontrol the egree of refrigeration imparte to the material or articlesplaced in said compartment 7. This control is of course subject more orless to the rate at which the gas is allowed to escape from the lowercompartment 7, and for this purpose, the refri eratorhas a bottom gasout et 13 with w ich is associated a suitable damper 14. The damper mayhave an actuating rod 15 adapted to be either manually orthermostatically operated, and in this way the rate of escape of the gasfrom the refrigerator may be regulated by varying the degree of openingof the damper 14. As shown, the refrigerator is provlded with aplurality of spaced adjacent guideways, arranged one above the other forslidable reception of the division or partition plates 12,

said guideways respectively communicatingwith slots in the front wall ofthe refrigerator through which the plates 12 are inserted. One or moreof the lates 12 may be inserted accordingto conditions met with in useof the apparatus. In order to minimize leakage of gas around the plates12 through the slots in the front wall of the refrigerator, said slotsmay be closed by means of a hinged door 16 having a facing of packingmaterial 17 upon its inner side adapted to tightly engage the front wallof the refrigerator and the adjacent outer ends of the plates 12 whenthe latter are in operative position and the door 16 is closed. Theouter ends of the plates 12 preferably carry handles: 18 arranged to bereceived in recesses 19 provided in the front wall of the refrigeratorwhen the plates 12 are operatively positioned, the recesses 19 beingsuiiiciently large to permit grasping of the handles 18 when the door 16is opened. In this way removal of the desired one or more of the plates12 may be readily accomplished.

It will be apparent that the number of plates 12 positioned betwieen thecompartments 6 and 7 will determine the effective thickness of theinsulation interposed between those compartments. However, it is readilyconceivable that the desired effect may be obtained in various otherways, and the use of a plurality of selectively removable plates ofinsulation is illustrated merely by way of example. At present, however,

In use, the desired number of insulating I plates 12 are positioned inplace, and after the material or articles to be refrigerated are plaeedwithin the lower chamber 7, the door 11 is tightly closed. The solidcarbon dioxide is then placed in the chamber 6 upon the 'support 8 andthe cover 9 tightly closed,

after which the damper 14 is opened to the desired degree. As heat isabsorbed from the surrounding atmosphere by the walls of therefrigerator, the solid carbon dioxide sublimates directl to a gas whichfalls to the bottom of the c amber 6. This gas chills the plates ofinsulation 12 as well as slowly see mg therethrough into the chamber 7.T e

lates 12 thus absorb heat from the chamber and the material or articlesplaced therein, thus refrigeratin to a material degree such material orartic es. To this refrigerating effect is added the direct action of thegas upon the material or articles as it passes down through the plates12 into the compartment 7 and in contact with the material or articlesto be refrigerated. The gas ultimate- 1y escapes from the lowercompartment 7 through the outlet 13 as governed by the damper 14, thelatter being opened according to existing conditions such as surroundingroom temperature, efliciency of the heat insulating walls of therefrigerator, etc. It can be approximately estimated thetemperaturewhich will maintain with the use of a given number of theplates 12 and a given degree of opening of the damper 14 when therefrigerator is used where substantially normal room temperaturemaintains, and thus the temperature produced in the chamber 7 may beregulated to a reasonable degreeor varied according to the nature of thematerial or articles to be refrigerated. While these conditions willvary slightly as the amount of solid carbon dioxide within the chamber 6is reduced, it is pointed out that such solid carbon dioxide willsublimate at a greater speed as its bulk is decreased thus offsettingthis variation to a great extent. It is accordingly believed that theconstruction, operation and advantages of the invention will be readilyunderstood andappreciated by those skilled in the art.

While the invention is shown as applied to refrigerators of the domestictype, it is to be understood that the invention does have a generalapplicability to cold storage plants, refrigerating cars and the like.

What I claim is:

1. In a refrigerating apparatus, an insulating receptacle and heatinsulating means of adjustable effective thickness dividing said sesamereceptacle into an upper chamber for reception of solid carbon dioxideand alower chamher for reception of material or articles to berefrigerated, said insulating means being of material slightly perviousto the gas evolved by sublimation of the solid carbon dioxide.

2. In a refrigerating apparatus, an insulating receptacle, a support forsolid carbon dioxide in the upper portion of said receptacle, and heatinsulation below said supportdividing said receptacle intonon-communicating upper and lower chambers respectively adapted forreception of solid carbon dioxide and the material or articles to berefrigerated, said heat insulation bein slightly pervious to the gasevolved by sub imation of the solid carbon dioxide and being adjustableto vary the effective thickness thereof at will.

3. In a refrigerating apparatus, an insulating receptacle, a support forsolid carbon dioxide in the upper portion of said receptacle, and heatinsulation below saidsupport dividing said receptacle intonon-communicating upper and lower chambers respectively adapted forreception of solid carbon dioxide and the material or articles to berefrigerated, said heat insulation being slightly pervious to thegasevolved by sublimation of the solid carbon dioxide and beingadjustable to vary the effective thickness thereof at will, saidreceptacle having an outlet for the escape of gas from the lowerchamber, and means for controlling the escape of gas through saidoutlet.

4:. A refrigerating apparatus comprising an insulated receptacle closedagainst free entry of air, a support for solid carbon dioxide in theupper portion thereof, and means to partition and adjustably heatinsulate the solid carbon dioxide from materials or articles to berefrigerated placed in the 'lower portion of said receptacle, saidpartitioning and insulating means being slightly pervious to the gasevolved by sublimation of the solid carbon dioxide, said receptaclehaving an outlet for the-escape of gas from the lower portion thereof,and means to control the escape of gas through said outlet. 5. Arefrigerating apparatus comprising a heat insulating receptacle closedagainst free entry of air, and heat insulation of adjustable thicknessbut of uniform thickness throughout its area when adjusted dividing saidreceptacle into non-communicating upper and lower compartmentsrespectively adapted for reception of solid carbon dioxide and articlesor the like to be refrigerated.

6. A refrigerating apparatus comprising an insulating receptacle,insulation of adjustable thickness but of uniform thicknessthroughoutits area when adjusted dividing said receptacle intonon-communicating upper and lower compartments respectively adapted forreception of solid carbon dioxide and articles or the like to berefrigerated, said insulation embodying a plurality of independentlyremovable division plates of material slightly pervious to the gasevolved by sublimation of the solid carbon dioxide, and means to permitand effect the controlled escape of said gas from the lower compartment.

7. A refrigerating apparatus comprising an insulating receptacle,insulation of adjustable thickness but of uniform thickness throughoutits area when adjusted dividing said receptacle into non-communicatingupper and lower compartments respectively adapted for reception of solidcarbon dioxide and articles or the like to be refri erated, saidreceptacle having a plurality 0 guideways arranged one above another andin alinement with slots in the front of the receptacle, said insulationembodying independently removable division lates insert- .able in andremovable from said guideways throu h said slots.

8. refrigerating apparatus comprising an insulating receptacle,insulation of adjustable thickness but of uniform thickness throughoutits area when adjusted dividing said receptacle into non-communicatingupor articles by evaporation of solid carbon dioxide, which includesplacing the solid carbon dioxide in the upper portion of an insulatedreceptacle which is closed against free entry of air, placing thematerial or articles in the lower portion of said receptacle,interposing a heat insulation which is.

slightly pervious to the gas evolved by sublimation of the solid carbondioxide between the solid carbon dioxide and the material or articles sothat the gas may pass to the lower portion of the receptacle only by seeage through said insulation, and varying t 0 effective thickness of saidheat insulation and permitting and controlling the escape of gas fromthe lower portion of the receptacle according to the degree ofrefrigeration desired.

10. The method of refrigerating materials or articles by evaporation ofsolid carbon dioxide, which includes placing the solid carbon dioxide inthe upper portion of an insulated receptacle which is closed againstfree entry 0 air and whose lower portion constitutes the space to berefri rated, entirely' dividing said portions 0 the rece tacle by meansof heat insulation sligh y pervious to gas evolved by sublimation of thesolid carbon dioxide, permitting restricted escape of the gas from thelower rtion of the receptacle, and varying the e ective thickness ofsaid heat insulation according to the degree of refrigeration desired.

In testimony whereof I afiix my signature.

JOSEPH S. BELT.

